The present invention relates to an internal combustion engine with a compression engine brake, said engine brake being utilized for exhaust gas recirculation.
In a conventional engine brake for an internal combustion engine as shown in FIG. 1, upon engine braking with an exhaust brake valve 10 being closed, a master piston 2 for a cylinder 7 is actuated through a rocker arm by a push rod 1 of another cylinder (not shown) to pressurize an oil having been supplied to an oil passage 5 from a rocker shaft support through solenoid and control valves 3 and 4. Then, the compressed oil urges a slave piston 6 to open an exhaust valve 8 adjacent to a top dead center of the cylinder 7 in a compression stroke and discharge the compressed air through an exhaust port 9, so that no force for pushing a piston in the cylinder 7 generates and a braking force obtained in the compression stroke is effectively utilized with no loss.
The conventional engine brake of this type, which is very effective for engine braking, cannot serve for exhaust gas recirculation and therefore cannot contribute to reduction of NO.sub.x and suppression of white smoke at engine starting. Generally, exhaust gas recirculation is difficult to effect especially in turbo-intercooled engines.
The reason for this is that; in most engine operating conditions, the intake manifold pressure is higher than the exhaust manifold pressure.
A primary object of the present invention is therefore to provide all internal combustion engine which overcomes the above-described problems.